1. Field of the Invention
The present invention relates to the field of collaborative computing and more particularly to user interface sharing in a collaborative environment.
2. Description of the Related Art
The rapid development of the Internet has led to advanced modes of communication and collaboration. Using the Internet as a backbone, individuals worldwide can converge in cyberspace to share ideas, documents and images in a manner not previously possible through conventional telephony and video conferencing. To facilitate collaboration over the Internet, a substantial collection of technologies and protocols have been assembled to effectively deliver audio, video and data over the single data communications medium of the Internet. These technologies include instant messaging, Internet telephony and application sharing.
In conventional application sharing, an application host can distribute imagery of an application operating in the host to one or more application viewers distributed about the computer communications network. The imagery can include not only the screens rendered in association with the operation of the shared application, but also the visual presentation of mouse pointer movements and the like. Generally, speaking, however, the imagery can include only discrete “snap-shots” of the actual display of the operating application in the host system. In this way, the application viewers can be given the appearance of sharing an application, though each viewer merely views a shadow rendering of only a portion of the operation of the shared application.
Pixel based application sharing technology allows the capturing of a series of images which represent the display of an application. The images can be transmitted across the computer communications network, which when rendered, can provide the illusion of duplicating the display of the application in its host environment. Nevertheless, the underlying technology used to support application sharing in this manner includes substantial limitations in that an entire application user interface or complete desktop user interface must be shared. For example, pixel based solutions like virtual network computing (VNC) provide facilities to share only portions of a user interface. In VNC, the pixels of a screen region are captured and transmitted to a remote station. However, VNC provides mere coarse-grained control over the user interface to be shared, while the user interface gratuity is a screen region, which brings some substantial limitations.
More particularly, pixel-based screen sharing requires more network bandwidth, for example, the size of data representing a fifty (50) by thirty (30) button is approximately one kilobyte. Secondly, it is very hard for the pixel-based screen sharing to understand the content of the user interface to be shared to meet the requirements of advanced operations, for example, to re-arrange the layout of the user interface to be shared to fit the form factor of the remote station, or to remove some of the private information from the user interface before transmitting the information. In consequence, sharing an application in a heterogeneous environment, where the form factors of devices are diverse, network capability is widely different and people have their personal privacy concerns, becomes a great challenge for the traditional pixel-based application sharing technologies.